Cerebral blood flow patterns underlying the differential impairment in category vs letter fluency in Alzheimer's disease
Cerebral blood flow patterns underlying the differential impairment in category vs letter fluency in Alzheimer's disease
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DOI：
10.1016/s0028-3932(99)00032-9
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发表时间：
1999-10-01
期刊：
影响因子：
2.6
通讯作者：
Prohovnik, I
中科院分区：
文献类型：
--
作者：
Keilp, JG;Gorlyn, M;Prohovnik, I
语言流畅性任务用于评估阿尔茨海默病（AD）患者的语言功能，并且随着疾病的进展，表现通常会下降。然而，一些研究表明，类别流畅性表现（从一个类别中产生单词）比字母流畅性表现（产生以某个字母开头的单词）下降得更快，这与其他痴呆症的情况不同。本研究的目的是确定这两种流畅性任务是否与AD患者脑血流异常的不同模式相关。对25名可能患有AD的患者和24名健康老年人进行静息、氙气吸入区域脑血流量测量（Xe-133 rCBF）和神经心理学评估。使用rCBF测量作为预测变量的逐步回归用于预测类别和字母流畅性的表现，无论是在合并组患者和对照组中，还是在单独的患者组中。还计算了rCBF变量与每个受试者在每个任务上的标准化校正分数之间的差异之间的相关性，这表征了它们之间差异的程度。在全样本回归中，类别和字母流畅性都是通过教育和左下顶叶血流下降（一种局灶性ad相关缺陷）来预测的。然而，类别流畅性的额外方差是由整体平均流预测的，而字母流畅性的额外方差是由正面流预测的。反过来，在患者样本中，类别流畅性的主要预测因子是平均流；字母流畅性的主要预测因子是左侧额叶流。流畅性差异评分分析显示，相对较大的流畅性类别损伤与更典型的ad相关的后颞叶和顶叶灌注缺陷相关。当两者受损程度相当时，典型的ad相关缺陷伴随着明显的额叶灌注缺陷。这些发现与这些任务的潜在神经心理学是一致的，并且表明类别流畅性与AD最典型的CBF缺陷有更强的关联，这说明它对这种疾病更敏感。另一方面，字母流畅性缺陷携带着灌注缺陷向额叶皮质扩散程度的重要信息。1999爱思唯尔科学有限公司版权所有。
Verbal fluency tasks are used to assess language functioning in Alzheimer's disease (AD), and performance typically declines as the disease progresses. However, several studies have shown that Category Fluency performance (produce words from a category) declines faster than Letter Fluency performance (produce words beginning with a certain letter), which is not the case for other dementias. The purpose of this study was to determine if each of these two types of fluency tasks was associated with different patterns of cerebral blood flow abnormality in AD. A resting, Xenon-inhalation regional cerebral blood flow measurement (Xe-133 rCBF) and neuropsychological evaluation was administered to 25 patients with probable AD and 24 healthy elderly controls. Stepwise regression using rCBF measures as predictor variables was used to predict Category and Letter Fluency performance, in both a combined group of patients and controls, and in the patient group alone. Correlations were also computed between rCBF variables and the difference between normatively corrected scores on each task for each subject, which characterized the extent of the discrepancy between them. In full sample regressions, both Category and Letter Fluency were predicted by education and the decline in left inferior parietal flow, a focal AD-related deficit. Additional variance in Category fluency, however, was predicted by global mean flow, while additional variance in Letter Fluency was predicted by frontal flow. Within the patient sample, in turn, the primary predictor of Category Fluency was mean flow; the primary predictor of Letter Fluency was left-sided frontal flow. Analysis of the fluency difference score revealed that relatively greater impairment of Category Fluency was associated with more typical, AD-related deficits in posterior temporal and parietal perfusion. When the two were equivalently impaired, typical AD-related deficits were accompanied by marked deficits in frontal perfusion. These findings are consistent with the underlying neuropsychology of these tasks, and suggest that Category Fluency's stronger association to the most typical CBF deficits of AD account for its greater sensitivity to this disease. Letter Fluency deficits, on the other hand, carry significant information about the degree to which perfusion deficits have spread to frontal cortex. (C) 1999 Elsevier Science Ltd. All rights reserved.